The paranasal sinuses are hollow cavities in the skull connected by small openings, known as ostia, to the nasal canal. Normally, air passes into and out of the paranasal sinuses through the ostia. Also, mucus is continually formed by the mucosal lining of the sinus and drains through the ostia and into the nasal canal.
Sinusitis is a general term that refers to inflammation in one or more of the paranasal sinuses. Acute sinusitis can be associated with upper respiratory infections or allergic conditions which cause tissue swelling and temporarily impedes normal trans-ostial drainage and ventilation of the sinuses, thereby resulting in some collection of mucous and possibly infection within the sinus cavities. Chronic sinusitis is a long term condition characterized by persistent or long term narrowing or blockage of the sinus ostia, resulting in chronic infection and inflammation of the sinuses. Chronic sinusitis is often associated with long standing respiratory allergies, nasal polyps, hypertrophic nasal turbinates and/or deviated internasal septum. While acute sinusitis is typically caused by infection with a single pathogen (e.g., one type of bacteria, one type of virus, one type of fungus, etc.), chronic sinusitis is often associated with multiple pathogen infections (e.g., more than one type of bacteria or more than genus of microorganism).
Chronic sinusitis, if left untreated, can result in irreparable damage to the tissues and/or bony structures of the paranasal anatomy. The initial treatment of chronic sinusitis usually involves the use of drugs such as decongestants, steroid nasal sprays and antibiotics (if the infection is bacterial). In cases where drug treatment alone fails to provide permanent relief, surgical intervention may be indicated.
Functional endoscopic sinus surgery (FESS) is commonly performed use an endoscope and various rigid instruments inserted through the patient's nostril. The endoscope is used to visualize the positioning and use of the operative instruments to perform tasks intended to improve sinus drainage, such as removal of polyps, straightening of deviated septum and excision of mucous membrane and bone to enlarge the narrow the sinus ostia or to create new openings into the sinuses.
Recently technique known as the Balloon Sinuplasty™ procedure has been developed by Acclarent, Inc. of Menlo Park, Calif. for treatment of sinusitis. A number of copending United States patent applications, including patent application Ser. Nos. 11/789,704, issued as U.S. Pat. No. 8,747,389 on Jun. 10, 2014, 11/355,512, issued as U.S. Pat. No. 8,894,614 on Nov. 25, 2014, 11/355,512, issued as U.S. Pat. No. 8,894,614 on Nov. 25, 2014, 11/150,847, issued as U.S. Pat. No. 7,803,150 on Sep. 28, 2010, 10/944,270, published as U.S. Publication No. 2006/0004323 on Jan. 5, 2006, and 10/829,917, issued as U.S. Pat. No. 7,654,997 on Feb. 2, 2010, describe various embodiments of the Balloon Sinuplasty™ procedure as well as various devices useable in the performance of such procedure. In the Balloon Sinuplasty™ procedure, a guide catheter is inserted into the nose and positioned within or adjacent to the ostium of the affected paranasal sinus. A guidewire is then advanced through the guide catheter and into affected paranasal sinus. Thereafter, a dilation catheter having an expandable dilator (e.g., an inflatable balloon) is advanced over the guidewire to a position where the dilator is positioned within the ostium of the affected paranasal sinus. The dilator is then expanded causing dilation of the ostium and remodeling of bone adjacent to the ostium, without required incision of the mucosa or removal of any bone. The catheters and guidewire are then removed and the dilated ostium allows for improved drainage from and ventilation of the affected paranasal sinus.
Parent application Ser. Nos. 11/789,704, issued as U.S. Pat. No. 8,747,389 on Jun. 10, 2014, 11/355,512, issued as U.S. Pat. No. 8,894,614 on Nov. 25, 2014, 11/150,847, issued as U.S. Pat. No. 7,803,150 on Sep. 28, 2010, 10/944,270, published as U.S. Publication No. 2006/0004323 on Jan. 5, 2006, and 10/829,917, issued as U.S. Pat. No. 7,654,997 on Feb. 2, 2010 also describe methods for transnasal dilation of other passageways in the ear, nose and/or throat, such as the Eustachian tube and nasolacrimal duct.